Because if you want to use these platforms this would mean you would have to prove your age.
Then I ask myself if I am wearing my tinfoil hat?
Sadly, nowadays, I am just not sure anymore.
It's just bribery, sorry I mean lobbying. Push this through, we make money and will fund your reelection.
They don't give a flying fuck about the children, they want to have total control over the citizens because all westerns countries are more or less slowly slipping towards authoritarianism.
Dictatorships in 21st century first world country will be impossible to topple, once the government can reliably link your ID to your online activity, you'll be arrested before you even know you'll commit an anti-governmental act.
Are governments good at regulating technology? Generally no. Is there a real problem that needs to be regulated: Oh my God, yes.